Sealing device for bottle caps



March 10, 1931. BUTCHER 1,795,289

SEALING DEVICE FOR BOTTLE CAPS 7 Original Filed Dec. 16, 1927 attorneys I evolving bottle-contents,

Patented Mar. 10, 1931 PATENT OFFICE CHARLES H. BUTCHER, OF CAMBRIDGE, MASSACHUSETT DEVICE FOR BOTTLE GAPS Beflled for abandoned application Serial No. 240,484, filed December 16, 1927. This application filed July 2, 1930. Serial No. 465,264.

I This invention relates to improvements in sealing devices for bottle caps.

' More particularly it relates to caps for sealing carbonated beverages, or other, gas

which tend to deteriorate by leakage and escape of gas.

This application is a substitute for my application Serial No. 240,434, filed December 16, 1927, which has become abandoned.-

The invention provides a cap so constructed that while the grip of cap on bottle may be released by a sharp blow applied to the cap, there is an improved structural arrangement by which the contents are held securely sealed against slow leakage until the cap is removed.

Bottles containing carbonated beverages must withstand severe internal gaseous pressures; and it is usual practice that the cap closure of the bottle is expected to withstand 115 pounds per square sure without leakage, which allows for normal variations in pressure and provides a margin of safety. To hold such a high pressure, the ordinary cap 15 secured to the bottle by a continuous depending skirt crimped under the rim of the bottle mouth. The tightness of the crimping makes it difiicult to remove the cap, so that the method of opening is to apply some form of special lever to lift the outside edge of the crimped skirt.

- It is an annoying occurrence when no suitable implement is at hand with which to open ones bottle; and therefore various devices have been proposed for dispensing with the need for such a special lever; but, so far as I am aware, none has hitherto been satisfactory. That is, none has proven itself commercially practicable for holding the contents secure underpressure and yet been releasable in a simple way, as by a simple blow. One idea which has been tried in various forms has provided an elastic bulge or mound on the top face of cap to-receive the blow, and a multiplicity of rim gripping elastic claws taking the place of the ordinary continuous, crimped depending skirt. But such claws,

separated and weakened by the cutting out sections of the skirt, and have proven has shown of intervening small capable of yielding resiliently, insuflicient. My exper menting inch of internal pres-' dome and claw that either the claws are not strong enough to hold the pressure satisfactorily; or, if made strong enough, the metal is too stifi for the cap to respond to the expected method of opening it by a blow. Another proposal provides a crimped skirt somewhat resembling that of usual type butcoupled with a raised central convex dome, and radial cuts at two or three equi-distant locations around the cap, extending essentially from the edge of the dome to the extreme outward edge of the cap. This also has proved impracticable and unsatisfactory, both because experience shows it does not hold the gaseous contents satisfactorily; and because the thrusting inward of the top of the mound by a blow, does not with certainty satisfactorily release the grip of crimped skirt on bottle.

\ It is a feature of the present invention that elements for engaging, for sealing and for releasing the bottle lip are combined in the cap in a novel way, such that the improved cap has both the quality of maintaining an effective seal and of being instantly openable by a smart blow on the head. It may be said, in a sense, that the advantages of the old construction are attained as regards ability of the cap to be opened by a blow on the head; and that the advantages of the old peripherally complete metallic skirt are attained as regards permanent strength and tightness of closure for retaining gases under pressure within thebottle; and that all disadvantages, found in one or the other of these old styles, are eliminated.

The improved cap can be applied by ordinary bottlecapping machines, whether hand or power operated, with no change in the machines mode of operation, and with no more than minor change in the machine structure. The caps themselves may be made according to usual practices, with only two additional steps which do not increase materially the total cost to produce the cap; or, by specially designed machinery the improved caps may be produced with no increase in the number of steps, and with no appreciable increase in construction cost.

The cap of the invention is made of substantially non-resilient metal, and comprises a closure disk provided with depending flange or skirt, much as is usual. The disk portion is formed with a central upward bulge, mound or dome, whose base is a little less in diameter than the inner edge circle of the glass which forms the mouth of the bottle; around which base is a plane annular portion, pressing down on the usual cork disk or wafer gasket arranged across the glass mouth of the bottle; and completely around this annulus is the peripheral depending crimped skirt. According to the invention the skirt is slitted at a few widely (not exceeding 90) separated locations around the cap, so that each skirt section thus made covers a considerable arc of curvature around the cap, and yet can freely swing outward as a unit, in a manner later to be explained. It is an important feature that each slit extends upward from the depending edge of the skirt to the angle between the skirt and the plane annulus; and

preferably the slit is formed without removalof any material. In a preferred form, in preparing the cap, each slit is made at an incline from vertical. Then when the cap is applied to a bottle, and the skirit is bent down from disk to depending cylindrical shape, the excess of metal makes each skirt section overlap its neighbors at each slit. thus at this place doubling the thickness of metal and materially enhancing the strength of grip of the cap on bottle rim. The overlying free edges of adjacent skirt portions at each slit re-inforce each other against any foreign force tending to thrust them outward from the bottle, as for example, the pressure of bottle rim when expansive force of bottle contents tends to drive the cap upward. But this overlying of skirt section edges inter-poses no obstacle at all if the skirt portions. voluntarily, as it were, tend to move simultaneously out from the bottle neck. Such a force and voluntary action is transmitted through the metal when a. blow is struck on the dome. The concussion from such a blow, delivered in axial direction toward the interior of the bottle, is transmitted to and depresses the annular base of the mound, whereupon, on principles of leverage, the depressing of this ase applies power at a lever arm distance from the glass which acts as a fulcrum, and swings the skirt sections like bell-cranks. Each skirt section depending from the bottle top swings radially outward. about its adjacent portion of the circular edge of the bottle as a fulcrum. The stitfness'and the consequent resistance of the metal forming the cap and its mound, which may be the same as is usual for bottle caps, is such that any mild blows encountered in ordinary handling are not sufficient thus to disrupt the cap.

Cooperating structural features relate to the position and extent of the slits. As to position, these are preferably distributed around the bottle rimv so that each skirt section shall have a continuous length of metal in pheripheral or angular direction which shall be as great as is feasible. Yet the angular length must not be so' great that one edge of a skirt section, considered as a bell crank and tending to move radially out from the bottle neck, tends to move in a direction too diverse from that in which the other edge of the same skirt section simultaneously tends to move radially. If so. the initial impulse is split into a diversity of mutually opposing forces, which exhaust the blow in a mere crushing or deforming of sheet metal, without actually freeing the cap. A location of the slits so as to divide the skirt into quadrants I have found feasible and preferable, while the making of any section substantially largerthan 90 introduces an internal state of conflicting stresses which interferes with satisfactory operation. Other details of importance including the oblique setting of slits, and the interlocking of sections by means of crimped slopes, are set forth hereinafter.

I have found that if the skirt slits are extended through the plane annulus to the base of the dome, a bottled carbonated liquid loses vigor; while if enclosed by a bottle cap embodying the present invention it retains full vigor. I believe the reason to be either or both that the cork combination gasket is not truly impervious, although commonly regarded as an adequate sealing agent; or that .he metal of the disk cannot maintain the necessary stiffness when the annulus compressing the cork on the glass rim is separated by radial slits instead of being a continuous annulus; but whatever the cause of the defective operation, the remedy is found by stopping the slits at the outer edge of the annulus. The construction thus stated provides a cap with mutually overlapping crimped skirt sections, but which, over and. within the bottle rim, is continuous and imperforate.

Caps made according to the present invention have withstood, without leaking, 180 pounds of internal pressure, which is 5 pounds more than the customary test pressures applied to bottled gas-evolving beverages. requiring a separate instrument as a releasing lever; and notwithstanding this powerful holding capability, the caps have been found removable neatly by mere concussion on the mound. in

It is intended that the patent shall cover, by suitable expression, in the appended claims, whatever features of patentable novelty exist in the invention disclosed.

In the accompanying drawings:

Figure 1 is a plan of a bottle cap embodying features of the invention and applied on a bottle;

Figure 2 is an elevation of the device of Figure 1, partly in medial section;

Figure 3 is an elevation, in medial section,

showing the cap mound or dome caved in, and the sections of crimped skirt flange swung out of engagement with the bottle rim; Figured is an elevation of a fragment of my improved cap greatly enlarged, showing the crimped flange prior to its being applied on a bottle, and showing a slit between skirt sections; and

Figure is a view similar to Figure 4, but showing the flange as it may look when applied on a bottle, with the skirt sections overlapping at the slits.

Referring to the drawings, the cap comprises a flanged .closure disk whose central portion 14 is pressed or otherwise formed to extend outward as a hollow mound. An annular plane portion 16 surrounds the mound and reaches a lever arm distance from the base of the mound to over the annular lip of the bottle mouth with which the cap is to be used, and continues outward slightly beyond the crest of the lip. From this plane annulus the flange of the cap depends as a crimped skirt 18, outside of the lip of the bottle, for engaging under the usual rim 17 or thickened portion of lip around the mouth of a bottle. Any usual or suitable cork on combination diskgasket 20 is employed within the cap to co-operate in effecting the necessary tight seal of the bottle mouth. a

The skirt 18 is divided by slits 22 which extend inward from the edge of the skirt to the place of junctureof skirt with the annular rin 16; Preferably four such slits 22 are use as shown in the drawings, spaced equally around the cap; but a. different number of the slits might be employed. The length of skirt section between slits must be great enough to give the section an inherently strong grip on the bottle, and must be not so great in an arcuate sense that the respective ends of any such section, in tending to move radially, receive impulses toomuch in opposition toeach other, or do not spread sufliciently away from the bottle when a. blow is delivered upon the mound 14, as later will be described. For example, in a section occupying 180 the terminal portions tend to swing in opposite directions, wheii they tend to swing out radially; and the mid-portion tends to swing in still another direction, 90 removed from each of theirs. If the. end

parts swing out. theyiiraw in the middle: or.

if the middle swings out, is must draw in the end parts. In either case'some portion of the skirt remains engaged with the bottle rim, because of the internal deformation of the skirt section. Or else the whole operation fails because the force derived from the cen- 66 tral blow is thus split into mutually opposing forces. A similar situation tends to arise if there are three slits at 120 apart; but I have found that this evil is so small as to be negligible if there are four sections each of l 490. In that case the ends of each section clear themselves of the bottle without trouble, and with free simultaneous movementin the directions of their several medial radii.

- The slits 22 are formed in the skirt without any removal of material. Preferably they are made in peaks or convex portions of the crimp rather than in the concavities or valleys; and they preferably extend at inclination from vertical as is clearly represented in the drawings. In the act of capping a bottle,

adj acent skirt sections 18 are'made to overlap each other slightly at the slits. This is possible because a cap, prior to its being applied to a bottle has its skirt flaring downward" with slits extending at inclines in peaks of the crimp, as seen at 22 in Figure 4. \Vhen the cap is subjected to the action of abottle capping device the skirt sections are forced toward and under the bottle rim 17, thus crowding flangematerial into a smaller circumference. and causing one edge of a slit to ride over the other, as indicated in Figure 5. By having the slits as shown, that portion of a slit peak-of-crimp which has the greater extent at the edge of skirt tends always to ride up over the other portion of the crimp, when the crimp is tightened, and so encases or locks down the terminal slope which it thus overlies of the next adjacent tions in peri heral direction. But this locking is not e ective against any radialmovement of the depending skirt section, under the leverage efiect incident to a blow applied to the mound 1%. As a result of this engagement of a peripherally complete skirt tightly under the bottle rim 1?, with continuously imperviousv metal annulus 16 overlying the top of the lip of the bottle, compressing the gasket 20 between it and the bottle, there is no possibility of pressure leaking out through the annular compacted portion of the gasket,

which underlies the ring 16, to the slits in the flange whose ends, in the act of capping, are forced slightly down over the-sides, as seen in Figures 2 and 5, where they are beyond the tightseal at the bottle mouth.

To be satisfactory the mound base circle must bdconsiderably smaller than the mouth of the bottle. and the slope of the mound should approach the plane annulus at a rather steep pitch. in order that both the gasket and the material of the cap may descend a little into the bottle mouth. on a line at a little distance within theinner edge of the glass top of bottle, and may be driven in that direction (instead of merely collapsing) upon receiving a blow on the crest. This provides the necessary leverage, about the rim as a fulcrum, and causes the applied force to be propcra'nks operate to swing in diverse directions and are not separate from each other, being Webbed imperviously continuous in the annulus over the bottle rim 15. This is a feature of construction Whose function and importance appear not to have been recognized heretofore. One result of prior efforts to make a cap releasable by concussion has been that the crimped skirt would not spread sufliciently to release the grip of the cap on bottle,

The powerful grip of an improved cap thus made may safely be released by the simple act of depressing the mound 14, either by striking the mound sharply With a stone or any club, or by butting the bottle against an obstacle. 'lhe concussion-forces the base of the mound slightly into the neck of the bottle, dishing in the annulus 16 whereby the sections of the'skirt 18, on leverage principles, individually move, each in its own radial direction, swinging s fliciently free of the bottle to permit easy removal of the cap.

I claim as my invention:

1. A metallic cap for a bottle comprising a closure having a ring portion over the bottle rim, and having an annular depending skirt flange whose Whole circumference is divided by slits into sections; said slits being made Without removal of metal, and terminating at the juncture of said ring and flange portions of closure; and said sections,

at each slit, having adjacent edges in overlapping engagement.

2. A metallic cap for a bottle comprising a closure having a ring portion over the bottle rim, and having an annular, crimped, de-

pending skirt flange Whose Whole circumfen ence is divided by slits into sections each of which approximates 90 of a circle; each said slit being formed in a peak of said crimp, all the original metal continuing present, and each terminating at the juncture of said ring and flange portions of closure; and the adjacent edges of said sections at each slit being in overlapping engagement, with one portion of a peak thus slit-engaging over the other portion of the same peak.

' 3. A metallic cap for. a bottle comprising a closure having a ring portion over the bottle rim, and having an annular, crimped, depending skirt flange whose Whole circumference is divided by slits into sections each of which approximates 90 of a circle; each said slit being formed at an incline in a peak of said crimp, all the original metal continuing present, and each terminating at the.

juncture of said ring and flange portions of closure; and the adjacent edges of said sec- 'tions at each slit being in overlapping engagement, with one portion of a peak thus slit reaching over the slope of the other portion of the same peak and locking said sec-,

below the level of the ring When knocked from above, whereby descent of the dome operates to free the skirt flange from the bottle neck.

Signed at Boston, Massachusetts, this 30th day ofJune, 1930. V

CHARLES H. BUTCHER.

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